The present invention relates to an apparatus for sealing a web of film. More specifically, the present invention relates to an apparatus for creating side seals in a web of film in a form, fill and seal packaging machine.
Typically, form, fill and seal packaging machines are utilized to package a product in a flexible container. To this end, form, fill and seal packaging machines are utilized to seal pharmaceuticals, dairy products, wine, food stuffs, cosmetics and other products in flexible containers. The form, fill and seal packaging machine provides an apparatus for packaging these products in an expedient manner.
In one type of form, fill and seal packaging machine a web of heat-sealable film is passed over a former or mandrel that forms the film into a tubular shape. To effect a tubular shape, the film is folded longitudinally and heat seal along abutting longitudinal edges. The tubular shaped film is then passed around a tubular fill system that deposits the product to be packaged into the tubular shaped film. To create individual packages (hereinafter "bags" ) the web of film must be sealed across its width. These side seals are typically created by a sealer that creates the second seal for one bag while making the first seal for the next bag. After the side seals are created, the web of film may then be severed between the seals to create individual bags.
It is sometimes desirous to create flexible containers filled with fluids that have attached thereto fitments. As used herein the term fitments includes, without limitation, ports, valves, and other means for accessing the fluid contained within the container. The fitments provide a means for accessing the container either via a spike, needle or valve contained on the fitment. Accordingly, the delivery characteristics of the fitment are important. The delivery characteristics are especially important in the medical industry where it is critical that the exact volume of drug prescribed is infused into the patient. Moreover, economic concerns encourage better delivery characteristics. Thus, it is desirable that the delivery characteristics of the bag and fitment are optimum in order to insure that the full contents of the bag are available.
One way to improve the delivery characteristics of a flexible container is to provide the container with chevrons on its bottom portion. The chevrons function to deliver the fluid to the fitment and thereby improve the delivery characteristics of the flexible container.
The creation of flexible containers with chevrons has at times been difficult because of the fitments that are attached to the web of film. In flexible containers where chevrons have been used in the past, those containers that have been made in form, fill and seal machines typically have had the chevrons created at a separate station from the side sealing station. Also, when the web of film is utilized to create a container filled with fluid, it has been difficult to put chevrons on the web of film due to the fluid which is housed within the containers.
Another problem suffered by some prior sealing apparatus is the failure of the gripper members. Typically, the jaws of the sealing apparatus include gripper members that allow the jaws to grip the web of film. Due to the forces and stresses on these gripper members they typically have a high failure rate. Accordingly, the gripper member must be changed at frequent intervals. This can be an especially costly procedure in aseptic form, fill and seal packaging machines wherein the aseptics of the system will be violated during each change.
Thus, there is a need for an improved sealing apparatus for sealing a web of film and creating chevrons.